The formation of absorbent articles for use as diapers, incontinent garments, feminine care products, etc., has generally involved the combination of a liquid-impermeable backing material, a liquid-permeable bodyside liner and an absorbent positioned therebetween. Body exudate, particularly menstrual fluid in the case of feminine napkins, which impinges upon the absorbent article is intended to pass through the liquid-permeable liner and be absorbed by the absorbent below. The liquid-impermeable backing material serves to prevent the exudate from passing through the article and staining the clothes of the wearer. It has been found that consumers in general do not prefer to look at the exudate absorbed by the article. Therefore, there is a desire to provide absorbent articles, particularly sanitary napkins, which contain a liquid-permeable liner that will mask the body exudate which comes in contact with it. The liquid-permeable liner must also exhibit the ability to rapidly transport body exudate therethrough.
Several alternatives have been proposed to make the liquid-permeable liner better at masking body exudate which comes in contact with it. In U.S. Pat. No. 4,333,979 issued to Sciaraffa et al., a spunbonded web is taught containing up to 5 percent of inorganic pigments so as to provide the liner with an opaque coloration. In U.S. Ser. No. 07/036,936 filed Apr. 10, 1987 by Datta et al. and assigned to Kimberly-Clark Corporation, a liquid-permeable nonwoven web is disclosed which is useful as a cover material for feminine pads. The web has a denier greater than 3 and has at least 1 percent of a colorant added to assist in masking body exudate. The web has an average pore size of about 15,000 to 100,000 square microns, an open area of about 25 to 50 percent and a weight of about 0.28 to 0.5 ounces per square yard. U.S. Pat. Nos. 4,341,213; 4,472,328; 4,483,897 and European Patents Nos. 0 140 560 and 0 172 420 all teach variations of adding pigments to the cover material.
A second alternative is to use a nonwoven fabric formed from a web of thermoplastic fibers having a plurality of apertures formed therein. The apertures allow fluid to pass through the liner while the nonapertured areas provide a masking effect. The liner can
also be embossed to provide a similar benefit, such as is taught in European Patent No. 0 164 740. A third alternative is to make the liner from a web which is intermittently and autogenously bonded at discrete bond areas. The use of unfinished polyolefin or polyester fibers can provide such a web texture as is disclosed in U.S. Pat. No. 3,886,942. Two variations of spunbonded facing webs having, a denier below 3, are taught in U.S. Pat. Nos. 4,077,410 and 4,519,799.
A fourth alternative is taught in European Patent No. 0 039 974 wherein a film topsheet containing a plurality of apertures overlays an intermediate layer having a multiplicity of tapered capillaries. The tapered capillaries are designed to draw fluid through the topsheet and into an absorbent below. One disadvantage of this design is that it requires a separate intermediate layer, which adds cost to the finished product.
In view of the above-identified prior art, there still exists a need to produce a liner which has its own unique properties such that it will allow body exudate, particularly menstrual fluid, to pass through it while masking the body exudate which is absorbed by the absorbent below. Now a nonwoven web has been invented which can accomplish the above.